\documentclass{standalone}
\usepackage{tikz}
\usepackage{ctex,siunitx}
\setCJKmainfont{Noto Serif CJK SC}
\usepackage{tkz-euclide}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{circuitikz}
\usetikzlibrary{patterns, calc}
\usetikzlibrary {decorations.pathmorphing, decorations.pathreplacing, decorations.shapes,}
\begin{document}
\small
\begin{circuitikz}[>=latex, scale=0.7]
  % \useasboundingbox(0.9,0)rectangle(5.1,5);
  \draw (6.5,0.5)--(0,0.5)node[below]{$c$} to [rmeter, t=G] (0,4.5)node[above]{$b$} --(6.5,4.5);
  \foreach \x in {1,2,...,6}
    \foreach \y in {1,...,4}
    {
      \node at (\x,\y){$\times$};
    }
  \draw [fill=white](3.5,0.2) rectangle (3.7,4.8);
  \draw [fill=white, dashed](5.5,0.2) rectangle (5.7,4.8);
  \node at (3.5,4.8)[left]{$a$};
  \node at (3.5,0.2)[left]{$b$};
  \node at (5.5,4.8)[left]{$a_1$};
  \node at (5.5,0.2)[left]{$b_1$};
\end{circuitikz}
\end{document}